Nd3+-deficiency double perovskite Nd1−BaCo2O5+ and performance optimization as cathode materials for intermediate-temperature solid oxide fuel cells

Abstract The high performance and robust durability of electrode materials are crucial requirements for intermediate-temperature solid oxide fuel cells. This study prepared a new type of Nd1−xBaCo2O5+δ+x/2Bi2O3 (x = 0.05, 0.1; NBC95+B, NBC90+B) composite cathode materials by introducing an Nd defect with bismuth oxide. The introduction of a bismuth oxide trace effectively increased conductivity and reduced the thermal expansion coefficient. The polarization impedance and maximum power density of the NBC95+B cathode were 0.026 Ω cm−2 and 720 mW cm−2 at 800 °C, respectively. The good electrochemical performance of the NBC95+B composite cathode is attributed to the introduction of Nd cation defects and the sub-oxidation state of Bi cations. Furthermore, the NBC95+B cathode exhibited good resistance to carbon dioxide poisoning.